Machine tool

Abstract

A machine tool has, on a machine bed, two stands which can be moved in the horizontal x- and z-direction, on which y-slides carrying tool spindles can be vertically moved. Arranged on one of the stands directly above a bridge projecting over its upper side is at least one tool magazine, with which a tool changer is associated for each stand. The drives for the y-slides are attached below the upper side of the stands to the stands.

The invention claimed is: 
     
       1. A machine tool,
 with a machine bed ( 1 ), 
 with a pair of x-guide rails ( 3 ) arranged on the machine bed ( 1 ) and extending in a horizontal x-direction, 
 with two x-slides ( 4 ,  4 ′) displaceably arranged for displacement in the x-direction on the x-guide rails ( 3 ), 
 with a respective z-slide ( 9 ,  9 ′) arranged on each x-slide ( 4 ,  4 ′) and displaceable in a horizontal z-direction extending perpendicular to the horizontal x-direction, 
 with a respective stand ( 13 ,  13 ′) arranged on each z-slide ( 9 ,  9 ′) with an upper side ( 21 ,  21 ′) and a front side ( 15 ,  15 ′), 
 with a respective y-slide ( 17 ,  17 ′) arranged on each front side ( 15 ,  15 ′) and displaceably arranged for displacement in a vertical y-direction extending perpendicular to the x-direction and to the z-direction up to close to the upper side ( 21 ,  21 ′),
 wherein each y-slide ( 17 ,  17 ′) is displaceable by means of a respective y-spindle spindle nut drive ( 22 ,  22 ′) and 
 wherein each of the y-spindle spindle nut drives ( 22 ,  22 ′) is rotationally drivable by means of a respective y-drive motor ( 19 ,  19 ′), which is arranged on the respective stand ( 13 ,  13 ′) below the respective upper side ( 21 ,  21 ′) thereof, 
 
 with a respective tool spindle ( 24 ,  24 ′) which is arranged on each y-slide ( 17 ,  17 ′), which each tool spindle
 is rotationally drivable about a respective rotation axis that extends in the z-direction, 
 is non-displaceable relative to the respective y-slide ( 17 ,  17 ′) in the z-direction and 
 has a tool holder ( 26 ,  26 ′) at an end of the respective tool spindle that is located in front of the respective front side ( 15 ,  15 ′), 
 
 with a working chamber ( 14 ) arranged in front of the front sides ( 15 ,  15 ′), 
 with a workpiece carrier ( 27 ) arranged in the working chamber ( 14 ) on the machine bed ( 1 ), 
 with at least one respective workpiece holder ( 30 ) associated with each stand ( 13 ,  13 ′) and arranged on the workpiece carrier ( 27 ), 
 with a common bridge ( 33 ) provided directly above the upper side ( 21 ,  21 ′) of each stand ( 13 ,  13 ′), 
 with at least one tool magazine ( 34 ,  34 ′) arranged directly above the upper sides ( 21 ,  21 ′) of the stands ( 13 ,  13 ′) on the bridge ( 33 ) and 
 with a respective tool changer ( 39 ,  39 ′) provided on the bridge ( 33 ) to transfer tools ( 37 ,  37 ′) from the at least one tool magazine ( 34 ,  34 ′) to the respective tool holder ( 26 ,  26 ′) and vice versa, the respective stand ( 13 ,  13 ′) being movable below the at least one tool magazine ( 34 ,  34 ′) for the tool change in such a way that the respective tool holder ( 26 ,  26 ′) is located below the respective tool changer ( 39 ,  39 ′). 
 
     
     
       2. A machine tool according to  claim 1 ,
 wherein each of the tool changers ( 39 ,  39 ′) has a change arm ( 41 ) which is pivotable about a respective pivot axis ( 40 ) extending in the z-direction and which each change arm is provided at each of its two ends with a tool gripper ( 42 ), and 
 wherein each of the y-slides ( 17 ,  17 ′) is movable in the y-direction towards the respective upper side ( 21 ,  21 ′) of the respective stand ( 13 ,  13 ′) to such an extent that one of the tool grippers ( 42 ) is drivable in front of the respective tool holder ( 26 ,  26 ′). 
 
     
     
       3. A machine tool according to  claim 1 , wherein the at least one tool magazine comprises two tool magazines ( 34 ,  34 ′), each of which is arranged directly above a respective one of the upper sides ( 21 ,  21 ′) of a respective one of the stands ( 13 ,  13 ′). 
     
     
       4. A machine tool according to  claim 1 , wherein each of the y-drive motors ( 19 ,  19 ′) is coupled to a respective one of the y-spindle spindle nut drives ( 22 ,  22 ′) by means of a respective belt drive ( 23 ,  23 ′). 
     
     
       5. A machine tool according to  claim 4 , wherein each of the belt drives ( 23 ,  23 ′) passes through a respective opening ( 23   a ) in a respective one of the stands ( 13 ,  13 ′). 
     
     
       6. A machine tool according to  claim 5 , wherein each of the openings ( 23   a ) is configured in a respective rear side ( 20 ) of a respective one of the stands ( 13 ).